The authors have evaluated the indications, methods and results of sphenoidal electrodes in epilepsy. This method makes it possible to study the hippocampal area which cannot be studied by extracranial electrodes. It also localizes in a temporal lobe complex seizures without electrical events, or complex seizures giving bilateral temporal spikes or a fronto-temporal focus of spikes. It may even show evidence of temporal focus in cases with bilateral and synchronous spikes. Thus, sphenoidal electrodes enable temporal seizures to be identified and localized, leading to more specific neuroradiological explorations and therefore helping in the selection of patients for specific surgery.